The bat broke in two with the force of the blow, which may have caused permanent disability, Superior Court Judge Kevin Smith said at the sentencing.

According to Gloucester County Prosecutor’s Office spokesman Bernie Weisenfeld, Prosser must serve five years, 11 months and 16 days (85 percent of his sentence) in prison before he’s eligible for parole.

Although Prosser was a juvenile at the time of the assault, a family court judge decided that he’d be tried as an adult. The victim, who had a relationship with Prosser’s mother, suffered several skull fractures, Weisenfeld said.

Smith pointed out the defendant’s mental health problems, which include diagnosed bipolar disorder and several suicide attempts. The judge warned that unless he deals with them, “specifically, his rage, equally or more serious crimes may be in his future.”